SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f781493955f8de0288ca452c1548329db3f99e485cd9e82c98c3f97c1516d1e1' 
  AND token = '2/iiFqIvJ70+VoY1mt8MOLsApliYa1h4XsC8hlNlYA0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00069

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}